The footage was captured on a Kansas City Police Dept. dash camera at around 9:30 PM on Feb. 4, 2021 ... just moments after Reid slammed his pickup truck into the back of a stopped car on a freeway near the Chiefs' practice facility in K.C.

You can see in the video, Reid -- who at the time was an assistant coach on his dad Andy Reid's Chiefs staff -- seemed to be walking and talking to an officer without issue.

Wearing a Chiefs COVID mask and a Chiefs sweatshirt, Britt obeyed all of a cop's commands ... even informing the officer he had consumed an Adderall-like medication roughly 13 hours before the wreck.

At one point, Britt appeared to experience some discomfort ... and after pulling up his shirt to examine his stomach, he calmly told an officer, "My front is starting to swell up a little." He ultimately asked to be checked out by medical personnel.

While waiting for an ambulance to arrive, Britt was informed that he'd be taken to a local medical facility. He then attempted to pull out his phone to inform someone of the news -- but a cop told him, "We can't be on the phone right now, OK?"

Britt responded, "My dad is sitting right there." The cop then told him he still couldn't be on the device, and Britt complied.

It's not clear if Britt meant Andy was at the scene -- a spokesperson for the KCPD told us on Wednesday they were not aware if the K.C. head coach was there.

As Britt and officers continued to wait for medics to arrive, the football coach could be heard in the video inquiring about 5-year-old Ariel Young, who suffered serious brain injuries in the crash.

"Any word on that little girl?" he asked.

"I have not heard anything, sir," the cop said.

Moments later, Britt appeared to pull something from his mouth and throw it onto the ground. He then spit several times.

An ambulance eventually came, and Britt got in it. Officials later said he required emergency groin surgery for his injury.

Days after the crash, authorities said in court documents Britt had a BAC of .113 moments after the wreck, well above the .08 legal limit. They also said they were able to determine he was going 82.6 MPH in a 65 MPH zone just seconds before the crash, and had reached 83.9 MPH at the time of impact.

Britt, who lost his job with the Chiefs in the days following the crash, was ultimately charged with felony DWI in the case.

He pled guilty to the count in September 2022 and was sentenced to three years in prison two months later.

At the sentencing hearing, Britt said he was sorry for his actions ... telling the courtroom, "Every time I see my daughter, I think about Ariel and how my decision affected her so deeply and her family."